The formation of residues attendant to etching is a problem which is well known in the semiconductor fabrication arts. Plasma processes prone to residue formation include polysilicon etches, metal etches, tungsten plug etch-backs, contact etches and via etches. Such residues, which are frequently polymeric and organometallic in nature, are known to increase resistance and to reduce device speed. Hence, the removal of these residues through a suitable cleaning process is a standard part of many commercial semiconductor fabrication processes.
Several cleaning processes have been developed in the art for the removal of such residues. These cleaning processes rely on a variety of organic solvents or aqueous based chemistries. For example, the use of cleaning chemistries based on dilute hydrofluoric acid or hydroxylamines are both well known in the art for the removal of etch residues.